How can I optimize my render times?
Every aspect of the time that a render takes is highly dependent on the setup of your scene, your render settings, and the hardware that you are rendering it with.

Are you rendering with Blender Internal, or Cycles? Blender Internal takes a long time to compute things like reflected light and ambient occlusion, and is limited to being able to render only on the CPU - and only on a single thread of the CPU for certain calculations. Cycles on the other hand, is much faster for computing reflected light and ambient occlusion, and can take advantage of a hardware acceleration on modern video cards to get hundreds of time better performance than rendering on the CPU.

The complexity of your meshes will effect the number of bounces a light path takes, and the complexity of your materials will effect the work that needs to be completed for each bounce. Try working through some tutorials on optimizing your renders.

For Blender Internal:
http://www.blenderguru.com/articles/13-ways-to-reduce-render-times/

For Cycles:
http://www.blenderguru.com/articles/4-easy-ways-to-speed-up-cycles/

You may also be giving each CPU thread or GPU too much or too little work to do with your render tile sizes. For CPU rendering, smaller is better - Something like 32x32 or 64x64 may work well. For GPU with Cycles, I have had good luck with 240x240 on my 780Ti's, and 240x120 on my 980's, and generally decent performance at 120x160 on all of my cards. You may need to explore which tile size works best for your scene setup. Here is what some other people have learned about tile sizes:

Best Tile Size for Blender Internal Renderer and Cycles

Even with computers thousands of times faster than what was available years ago, patience is still a virtue. I run a render farm at home with 4 machines with 3 modern video cards each, but due to the complexity in my scenes, I have to set my renders to run on all of my boxes overnight to render about 5 seconds of full HD video.

You will also get answers closer to what your looking for if you can be more descriptive of your scenario, of your scene setup, your render settings, and possibly even provide some screenshots of the scene in your blend file when you ask questions moving forward. Good luck!